astute - Ability to understand things quickly and clearly, and to use the knowledge well
From a very early age, Gail instinctively knew everything about business, and and after college she proved to be an astute business woman, and became a millionaire before the age of 30.
sober - Serious and thoughtful in mood or behavior, not playful or exaggerated; or not under the influence of alcohol or drugs; clear-minded.

It was a year since he gave up drinking and had decided to remain sober all the time, and it took strength to just walk past the bar.